Question

我创建了一个http服务器。在创建服务器之前，我检查数据库连接。如果db已关闭..将再次调用check方法，直到它连接为止。在此之后我启动服务器。启动服务器后，我需要检查几个配置设置。服务器启动正常。我编写了一个代码，用于依次调用3个配置设置验证码。但是，两个方法同时执行，最后一个方法根本不被调用。

//检查与其他应用的连接

function checkconfig1() {
    return request.post({
        headers: {
            'content-type': 'application/json'
        },
        url: url,

    }, function(error, response, body) {

    if (body == 'success') {
        //config 1 is verified
        console.log("config 1 is verified")

    }
    if (error) {
        console.log("config 1 is not correct")
        return Promise.delay(2500).then(checkconfig1);
    }
});

 }
 function checkconfig2() {

return request.get({
    headers: {
        'content-type': 'application/json'
    },
    url: url,

}, function(error, response, body) {

    if (error) {
        console.log("config 2 is not correct")
        return Promise.delay(2500).then(checkconfig2);
    } else {
        console.log("config 2 is verified")
    }

});

 }

     function checkconfig3() {
        var cmd = 'somecommand';
        return exec(cmd, function(error, stdout, stderr) {

            if (error) {
                console.log("config 2 is not correct")
                return Promise.delay(2500).then(checkFonts);
            } else {
                console.log("config 2 is verified")
            }

        });
     }

 module.exports = function() {

    return checkconfg1().then(checkconfig2).then(checkconfig3());
    //return checkFonts();
 }

我做得对吗？任何人都可以解释如何做到这一点？感谢

Answer 1

我已经修改了一下你的代码。你能试试这个：

function checkconfig1() {
    return new Promise(function (resolve, reject) {
        request.post({
            headers: {
                'content-type': 'application/json'
            },
            url: url,

        }, function (error, response, body) {

            if (body == 'success') {
                //config 1 is verified
                console.log("config 1 is verified")
                return resolve();

            }
            if (error) {
                console.log("config 1 is not correct")
                return resolve(Promise.delay(2500).then(checkconfig1));
            }
        });
    });
}
function checkconfig2() {

    return new Promise(function (resolve, reject) {
        request.get({
            headers: {
                'content-type': 'application/json'
            },
            url: url,

        }, function (error, response, body) {

            if (error) {
                console.log("config 2 is not correct")
                return resolve(Promise.delay(2500).then(checkconfig2));
            } else {
                console.log("config 2 is verified")
                return resolve(response);
            }

        });

    });



}

function checkconfig3() {
    var cmd = 'somecommand';
    return new Promise(function (resolve, reject) {
        exec(cmd, function (error, stdout, stderr) {
            if (error) {
                console.log("config 2 is not correct")
                return resolve(Promise.delay(2500).then(checkFonts));
            } else {
                console.log("config 2 is verified")
                return resolve();
            }

        });
    });
}

module.exports = function () {
    return checkconfig1().then(checkconfig2).then(checkconfig3);
    //return checkFonts();
};

同步方法调用不使用promise - nodejs

1 个答案: